Abstract: A method and separation device for removing PCR inhibitors from whole blood or plasma/serum, is provided. The disclosed embodiments include the separation device; and system for removing PCR inhibitors and separating PCR inhibitors from nucleic acids, such as DNA or RNA, and the other components found in whole blood or plasma/serum samples, and methods of making and using the same, so that uncontaminated DNA/RNA is replicated. The separation device comprises: a receptacle for holding whole blood, serum or plasma samples; and a physical substrate for binding and removing one or more PCR inhibitors from the sample matrices, and glass capillary tubes. Physical substrates comprise, e.g. a crosslinked copolymer comprising acrylamide and N,N?-Methylenebisacrylamide, and one or more derivatives of acrylamide and acrylate with glycerol; and non-acrylamide based polymers such as sodium alginate or polyvinyl alcohol with agarose. And the receptacle comprises, e.g.